1. Field of Invention
The present invention relates to a method for solving a mismatched negotiation result between an auto-negotiation mode and an enforce mode in the Ethernet. More particularly, the present invention relates to a method for solving a mismatched negotiation result between an auto-negotiation mode and an enforce mode of network components connected in a full duplex or half duplex mode in a 10/100 Mpbs Ethernet.
2. Description of Related Art
Currently, operation modes for a network card/adaptor includes four modes: 100 Mbps full duplex mode (100FDX), 100 Mbps half duplex mode (100HDX), 10 Mbps full duplex mode (10FDX) and 10 Mbps half duplex mode (10HDX). The full duplex mode can receive and transmit simultaneously in a network, while the half duplex mode can only receive or transmit at the same time.
Most network cards on the market currently can be operated under the aforementioned four operation modes, but an additional auto-negotiation mode is further provided to allow compliancy with older network cards/adaptors. The auto-negotiation mode is used for detecting an operation mode performed on a remote network card in the network, and automatically adjusts the local network card to a best operation mode. Furthermore, in addition to the auto-negotiation mode of the current network card, users can set the network card for an enforce mode; i.e., the users can enforce the network card to be operated in any one of the 100FDX, 100HDX, 10FDX and 10HDX modes.
Assume that when the local device is connected to the remote device in the Ethernet system, the remote device is operated in the auto-negotiation mode, and the local device is enforced to be the 100FDX mode by the user. A parallel detection function of the auto-negotiation mode of the remote device is capable of detecting a most suitable transmission rate between the remote and the local devices. However, the remote device cannot recognize whether the local device is operated in the HDX or FDX mode. If the transmission rates respectively for the local and the remote devices are the same, the network status is set to be a normal connection. Accordingly, the remote device is then set to the 100HDX mode to perform packet receiving and transmitting operations with the local device. Due to different operation modes used at the local and remote devices, packet loss occurs while receiving and transmitting between the local and the remote devices.
FIG. 1 is flow chart illustrating a conventional method for setting a network card/adaptor to operate in an enforce mode. Referring to FIG. 1, at step 102, a local computer is set in a disconnect status and the auto negotiation mode is turned off. Next, at step 104, a transmission rate and the FDX/HDX modes are set. Then, at step 106, the local computer is reset to a connect status.
Referring to Table I, the connection status and the packet lost are listed while the local and the remote devices are set for various operation modes. In Table I, the column is the mode set of the local device, and the row is the mode set of the remote device. Packet loss results from that the parallel detection function of the auto-negotiation mode of the local device only detects that the transmission rate of the remote device is 10 Mpbs or 100 Mbps, but cannot recognize the remote device is operated in the HDX or FDX mode. Therefore, as seen from Table I, in some cases, the remote and the local devices are normally connected, labeled “yes” in the connection status field, however packet loss still occurs, labeled “yes” in the packet loss field. For example, when the user enforces the local device to be the 100FDX mode and the remote device is in the auto detection mode, packet loss occurs.
TABLE IAutomode setNego-(local/remote)tiation100FDX100HDX10FDX10HDXAutoconnec-YesyesyesYesyesNego-tiontiationstatuspacketNoyesnoYesnoloss100FDXconnec-YesyesyesNoNotionstatuspacketYesnoyesloss100HDXconnec-YesyesyesNonotionstatuspacketNoyesnoloss10FDXconnec-YesnonoYesYestionstatuspacketYesNoYesloss10HDXconnec-YesnonoYesyestionstatuspacketNoYesnoloss